How do I get home assistant to see any smart devices in the LAN? It should see WIFI and Zigbee devices.
Thanks
The DOCS is a good place to start , Beside READ the very first post in this Forum, before starting Open Posts
The Very first Post … Guidelines to avoid repeated Post/Topics, and Then Ofcause there is the Search Function ( Works kind of like Google, with the benefits that you can search the whole Forum or in Specific Topics ( Filtering )
How to help us help you - or How to ask a good question. Forum Guide Lines ! " Click And Read ! ( After you read the Getting Started DOCS )
The " magnifying glass " to the right is not for Expanding the text, It’s The Search Function, Which you should use after you read the Onboarding Docs / And The Integration Section in same Docs “Getting Started”
Depends on the device. Many (most) WiFi devices only work with a cloud API.
Those aren’t on your LAN. What are they connected to right now?
If they’re not connected to anything you need to buy a Zigbee coordinator, set up ZHA (or Zigbee2MQTT), and then manually pair them all.
I already have a network working with Wifi smartdevices and Zigbee smartdevices. I already have a Zigbee hub. Most devices are configured in alexa. Just a few do not work with Alexa and only work with Tuya.
How can I fix this so that all, both alexa devices and Tuya devices, are recognized by home assistant?
Thanks
What hub? Help us help you by giving us actual details 
Tuya is … “easy”, use the Tuya integration. The downside is that it uses their cloud API and relies on Tuya supporting things correctly. Odds are 50/50 whether that’ll be a good experience or not.
Alexa… yeah, that’s not going to happen. Amazon don’t allow you to expose devices to other systems.
This is my hub: MOES Tuya ZigBee Smart Gateway/Hub with ethernet cable to reach the router.
I installed home assistant in Docker in Windows and it seems that might be the reason why home assistant does not see the smart devices in the LAN. Anyway, I installed HA afterwards in Oracle VM VirtualBox and this HA installation does not see the wifi or zigbee devices either.
I said Tuya, but some of them are also MOES. I just know all of them are Chinese brands such as these two brands I mentioned. I do not remember if all devices are of these brands though. I do know all of them are cheap Chinese brands.
I thought Home assistant was easy to integrate all wifi and Zigbee devices regardless of their brand.
So far I just was using the Alexa app or MOES app to manage all the devices.
You need to add all your devices to either the Smartlife app or the Tuya app. And then install the Tuya integration in HA.
Moes is still Tuya. Tuya makes a lot of stuff that others re-badge as their own, and also sell services for design, build, firmware, and their SmartLife platform.
As Francis said, you’ll need to use the Tuya integration.
HA won’t “see” any of those devices unless you do so.
Currently I have all my devices in the MOES app. Do I need to change all devices from the MOES app to the Tuya app?
Yes, you do.